Car air conditioner and car with its conditioner

ABSTRACT

There is provided a car air conditioner with a high COP, low GWP and high reliability. A simple refrigerant R 32  is filled in a refrigerant circuit  1  of the car air conditioner. This simple refrigerant R 32  has a high COP and low GWP, but is easily polarized and produces contaminants and sludge. However, these contaminants and sludge hardly block a motor-driven expansion valve  6  or the like due to vibration and impact of a car. Therefore, this car air conditioner has high reliability. Furthermore, since the simple refrigerant R 32  is a simple substance, recycling after collection is easy.

TECHNICAL FIELD

[0001] The present invention relates to a car air conditioner and a carequipped with this car air conditioner.

BACKGROUND ART

[0002] In a conventional car air conditioner, a refrigerant circuit isfilled with an incombustible refrigerant R134 a in view of safety.

[0003] Meanwhile, at the Kyoto COP3 conference, manufacturers of airconditioners were strongly required to prevent discharge ofrefrigerants, collect refrigerants and improve a COP (coefficient ofperformance) in order to prevent global warming.

[0004] However, since an incombustible refrigerant R134 a is used in aconventional car air conditioner, the refrigerant R134 a is low ability(that is, its COP is low) and hence a compressor is large. Therefore,there is a problem that 20-30 wt % of the total fuel consumption of acar is consumed by the air conditioner, resulting in high GWP (globalwarming potential).

DISCLOSURE OF THE INVENTION

[0005] Accordingly, an object of the present invention is to provide acar air conditioner with a high COP and low GWP and a car using thesame.

[0006] In order to achieve the above object, a first aspect of theinvention provides a car air conditioner, wherein a single refrigerantR32 is filled in a refrigerant circuit.

[0007] It is noted that, in the present specification, the singlerefrigerant R32 refers to one substantially recognized as a singlerefrigerant R32 by those skilled in the art and may naturally contain atrace of a stabilizer or additive.

[0008] Since the car air conditioner of the present invention uses thesingle refrigerant R32, its COP is high in comparison with aconventional car air conditioner using the refrigerant R134 a.Therefore, the volume of a cylinder of a compressor can be reduced, thecar can be lightened, and thus improvement of the fuel consumption canbe achieved.

[0009] Furthermore, since the car air conditioner of the presentinvention uses the single refrigerant R32 with a low GWP, global warmingcan be prevented.

[0010] Furthermore, since the single refrigerant R32 is slightlycombustible, there are few car fire hazards.

[0011] Furthermore, since the single refrigerant R32 is a simplesubstance, recycling after collection is easier than the case of a mixedrefrigerant. This easiness of recycling after collection provides anextremely great advantage to a car air conditioner of cars, which arescrapped in several years to over 10 years at the longest.

[0012] Since the single refrigerant R32 is an HFC refrigerant and haspolarity, contaminants and sludge are easily produced and may block acapillary, motor-driven expansion valve or the like. Therefore, it wasnot considered to use this refrigerant for a car air conditioner ofcars, which particularly require reliability. However, the inventors ofthe present invention found that, even when contaminants and sludge wereproduced from the single refrigerant R32, the contaminants and sludgedid not block the capillary, motor-driven expansion valve or the likedue to vibration and impact of the car. The present invention is basedon this finding.

[0013] A second aspect of the invention provides a car air conditioner,wherein a mixed refrigerant containing R32 at 70 wt % or more is filledin a refrigerant circuit.

[0014] According to the car air conditioner of the present invention,since a mixed refrigerant containing R32 at 70 wt % or more is used,there is some difficulty in recycling after collection in comparisonwith the single refrigerant R32, but the difficulty was withintolerance. Except for this, almost the same functions and effects asthose of the car air conditioner of the first aspect of the inventioncan be obtained.

[0015] In one embodiment, the refrigerant circuit includes a scrollcompressor or rotary compressor.

[0016] According to the car air conditioner of this embodiment, a scrollcompressor or rotary compressor is used for the refrigerant circuit. Itwas found that this scroll compressor or rotary compressor is the mostsuitable to a car due to its small sliding area in view of durabilityand light weight when the single refrigerant R32 or mixed refrigerantcontaining R32 at 70 wt % or more is used.

[0017] In one embodiment, the rotary compressor is a swing-type rotarycompressor in which a roller revolves in a cylinder and a blade which isfixed to the roller separates a suction chamber and a compressionchamber.

[0018] In the rotary compressor of the car air conditioner of thisembodiment, since the blade fixed to a roller separates into the suctionchamber and the compression chamber, and the blade is fixed to theroller and is not brought into line contact with the roller, this carair conditioner has high durability and can contribute to lightening ofa car in relation to the single refrigerant R32 or mixed refrigerantcontaining R32 at 70 wt % or more.

[0019] In one embodiment, the refrigerant circuit includes a refrigerantcollection port.

[0020] Since this car air conditioner of this embodiment has therefrigerant collection port, the refrigerant can be easily collected.

[0021] In one embodiment, the refrigerant circuit includes ahigh-pressure dome-type compressor in which a motor and a compressingpart are disposed in a casing and a high-pressure refrigerant is filledat least in a space in the casing in which the motor exists.

[0022] In one embodiment, the refrigerant circuit includes alow-pressure dome-type compressor in which a motor and a compressingpart are disposed in a casing and a low-pressure refrigerant is filledat least in a space in the casing in which the motor exists.

[0023] In one embodiment, the refrigerant circuit includes a fullyclosed compressor.

[0024] In one embodiment, the refrigerant circuit includes a semi-closedcompressor.

[0025] In one embodiment, the refrigerant circuit includes an opencompressor.

[0026] All the compressors of the car air conditioners of the aboveembodiments have favorable compatibility with the single refrigerant R32or mixed refrigerant and can sufficiently function.

[0027] A car according to a third aspect of the invention is equippedwith any one of the above car air conditioners.

[0028] Since the car of the present invention is equipped with the carair conditioner, this car not only has advantages of light weight andlow fuel consumption, but also can satisfy requirements such ascollection of the refrigerant and recycling.

[0029] In one embodiment, the car air conditioner is hardly ignited evenif the refrigerant leaks.

[0030] The car of this embodiment has an advantage that there are fewfire hazards.

[0031] In a car according to one embodiment, a partition plate isdisposed between the car air conditioner and an ignition source.

[0032] Since the car of this embodiment has a partition plate betweenthe car air conditioner and the ignition source, the leaked slightlycombustible refrigerant is not ignited even if the slightly combustiblerefrigerant leaks from the car air conditioner. Therefore, this car issafe.

[0033] In a car according to one embodiment, a guide member for guidinga refrigerant that leaks from the car air conditioner to the outside isincluded.

[0034] In the car of this embodiment, since the leaked refrigerant isguided to the outside by a guide member even if the slightly combustiblerefrigerant leaks from the car air conditioner, the leaked refrigeranthas a lower concentration and thereby is not ignited. Therefore, thiscar is safe.

[0035] In a car according to one embodiment, any driving motor of anelectric motor, gasoline-powered engine or hybrid-type engine isincluded.

[0036] Since the car of this embodiment is equipped with theaforementioned car air conditioner, whether the drive motor is anelectric motor, gasoline-powered engine or hybrid-type engine, this carhas advantages of having light weight and low fuel consumption as wellas efficiency resulting in a long travel distance per charge. Inparticular, when the electric motor or hybrid-type engine is used, thetravel distance per charge can be extended, and the effect is extremelyhigh.

BRIEF DESCRIPTION OF THE DRAWINGS

[0037]FIG. 1 is a refrigerant circuit diagram of a car air conditioneraccording to an embodiment of the invention;

[0038]FIG. 2 is a vertical cross sectional view showing a scrollcompressor used for this embodiment;

[0039]FIG. 3 is a plan view showing a fixed scroll and a movable scrollof the scroll compressor;

[0040]FIG. 4 is a vertical cross sectional view showing a rotarycompressor;

[0041]FIG. 5 is a horizontal cross sectional view showing a portionwhere a roller exists in the rotary compressor of FIG. 4;

[0042]FIG. 6 is a cross sectional view showing a substantial portion ofa swing-type rotary compressor;

[0043]FIG. 7 is an explanatory view showing a high-pressure dome-typecompressor;

[0044]FIG. 8 is an explanatory view showing a low-pressure dome-typecompressor;

[0045]FIG. 9 is an explanatory view showing a car according to anembodiment of the invention; and

[0046]FIG. 10 is an explanatory view showing a car according to anotherembodiment of the invention.

BEST MODE FOR CARRYING OUT THE INVENTION

[0047] Hereafter, embodiments of the present invention will be describedin detail with reference to the accompanying drawings.

[0048] As shown in FIG. 1, a car air conditioner of this embodimentincludes a refrigerant circuit 1 constituted by a scroll compressor 2,four-way changeover valve 3, outdoor heat exchanger 5, motor-drivenexpansion valve 6 and indoor heat exchanger 7, which are successivelyconnected. A refrigerant collection port 8 is disposed between theoutdoor heat exchanger 5 and the motor-driven expansion valve 7 in thisrefrigerant circuit 1. This refrigerant circuit 1 is filled with asingle refrigerant R32.

[0049] The scroll compressor 2 is a so-called low-pressure dome-typescroll compressor, which has a structure shown in FIGS. 2 and 3. Thislow-pressure dome-type scroll compressor 2 has a fixed scroll 21 and amovable scroll 22 in a dome-type casing 20 and drives the movable scroll22 with a crank shaft 23. This crank shaft 23 is driven by a motor 25disposed in the casing 20. The single refrigerant R32 sucked from asuction port 26 is filled in a space where the motor 25 exists, furthersucked between the fixed scroll 21 and the movable scroll 22, compressedand discharged from a discharge port 28.

[0050] In the car air conditioner having the above constitution, sincethe single refrigerant R32 is filled in the refrigerant circuit 1, itsCOP is high in comparison with a conventional car air conditioner usingthe refrigerant R134 a, and thus the volume of the compressing part(cylinder) of the compressor 2 is smaller than a conventional one.Therefore, improvement of fuel consumption of a car can be achievedsince motive power required for this car air conditioner itself can bereduced and a car on which this car air conditioner is mounted can belightened.

[0051] Furthermore, in the car air conditioner of this embodiment, sincethe single refrigerant R32 with a low GWP is filled in the refrigerantcircuit 1, influence on global warming can be minimized even if thesingle refrigerant R32 leaks from the refrigerant circuit 1.

[0052] Furthermore, since the single refrigerant R32 is slightlycombustible, there are few car fire hazards.

[0053] Furthermore, a car air conditioner is scrapped at the end of lifeof a car. Upon the scrap, the single refrigerant R32 can be readilyremoved from the refrigerant collection port 8 of the car airconditioner. Since this single refrigerant R32 is a simple substance,recycling after collection is easy in comparison with a mixedrefrigerant. This easiness of recycling after collection provides anextremely great advantage to a car air conditioner of a car, which isscrapped in several years or over 10 years at the longest.

[0054] Furthermore, since the car air conditioner is mounted on a car,it receives vibration and impact together with the car. Therefore, itwas found that, even when contaminants and sludge were produced due tothe polarity of the single refrigerant R32, the vibration and impactprevented contaminants or sludge from attaching to the motor-drivenexpansion valve 6 or the like. Therefore, this car air conditioner hashigh reliability.

[0055] It is noted that the single refrigerant R32 is mixed with arefrigerating machine oil such as an alkyl benzene oil or the like.

[0056] It was found that the scroll compressor 2 had favorable lubricityand durability in relation to the single refrigerant R32.

[0057] In the above embodiment, the single refrigerant R32 is filled inthe refrigerant circuit 1, but a mixed refrigerant containing R32 at 70wt % or more may be filled instead of the single refrigerant R32. Here,in the mixed refrigerant containing R32 at at least 70 wt %, R125, R22,a carbon dioxide gas or the like is used as the remaining refrigerant.

[0058] In this case, there is some difficulty in recycling aftercollection in comparison with the single refrigerant R32, but thedifficulty was within tolerance. Except for this, almost the samefunctions and effects as those of the single refrigerant R32 wereobtained.

[0059] It was found that, when a high-pressure dome-type rotarycompressor 30 shown in FIGS. 4 and 5 was used instead of thelow-pressure dome-type scroll compressor 2, lubricity and durabilitywere also favorable in relation to the single refrigerant R32 or mixedrefrigerant containing R32 at 70 wt % or more. In particular, it wasfound that the high-pressure dome-type rotary compressor 30 couldcontribute to improvement of lightening and low fuel consumption of acar along with the use of the single refrigerant R32 with a high COP orthe mixed refrigerant containing R32 at 70 wt % or more.

[0060] In the high-pressure dome-type rotary compressor 30, as shown inFIGS. 4 and 5, a motor 32 is disposed in a dome, that is, a casing 31,and a crank shaft 33 is driven by this motor 32 to create a planetarymotion of a roller 35 in a cylinder 34. As shown in FIG. 5, the blade 36is pressed on a peripheral surface of the roller 35, and the cylinder 4is partitioned into two chambers. By the planetary motion of the roller35, a low-pressure refrigerant sucked from a suction port 37 iscompressed and discharged into the casing 31. A high-pressurerefrigerant is filled in the casing 31 and discharged from a dischargepipe 39 to the outside. It is noted that reference numeral 38 denotes anaccumulator.

[0061] It is more preferable to use a swing-type rotary compressor 40shown in FIG. 6 instead of the high-pressure dome-type rotary compressor30. In the rotary compressor 30 shown in FIGS. 4 and 5, the roller 35and the blade 36 are separate elements, while a roller 43 and a blade 44are integrated in the swing-type rotary compressor shown in FIG. 6.Swing bushes 45, 45 shaped in a semicircular pillar are brought intosurface contact with both surfaces of this blade 44 to achieve sealing.In the cylinder 42 disposed in the casing 41, the roller 43 formedintegrally with the blade 44 revolves to perform a compression action.

[0062] It was found that, since the blade 44 is fixed to the roller 43revolving in the cylinder 42 and is brought into surface contact withthe swing bushes 45, 45 shaped in a semicircular pillar, the swing-typerotary compressor 40 had the most excellent lubricity and durability inrelation to the single refrigerant R32 or mixed refrigerant containingR32 at 70 wt % or more among rotary compressors.

[0063] It was also found that both the high-pressure dome-typecompressor and the low-pressure dome-type compressor had favorablecompatibility with the single refrigerant R32 and the mixed refrigerantand could sufficiently function. In the high-pressure dome-typecompressor, as shown in FIG. 7, a motor 51 and a compressor 52 aredisposed in a casing 53, and a high-pressure refrigerant is filled atleast in a space in the casing 53 where the motor 51 exists. Thelow-pressure refrigerant from an accumulator 55 is sucked into acompressing part 52 through a suction pipe 56, and the high-pressurerefrigerant is filled in the casing 53 and discharged from a dischargepipe 57 to the outside.

[0064] Meanwhile, in the low-pressure dome-type compressor, as shown inFIG. 8, a motor 61 and a compressor 62 are disposed in a casing 63, anda low-pressure refrigerant is filled at least in a space in the casing63 where the motor 61 exists. The low-pressure refrigerant from anaccumulator 65 is sucked into the casing 63 through a suction pipe 66,and the low-pressure refrigerant in the casing 63 is sucked into acompressing part 62, compressed and discharged from a discharge pipe 67to the outside.

[0065] Furthermore, it was found that a fully closed compressor,semi-closed compressor and open compressor also had favorablecompatibility with the single refrigerant R32 and the mixed refrigerantand could sufficiently function. In the fully closed compressor, boththe compressor and the motor are disposed in a sealed casing filled witha refrigerant. Furthermore, in the semi-closed compressor, a part of acompressor is disposed in a sealed casing filled with a refrigerant.Furthermore, in the open compressor, the motor and the compressor areopen to the outside without using a sealed casing.

[0066] In FIG. 9, the car air conditioner of the embodiment shown inFIG. 1 (designated as 100 in FIG. 9) is mounted on a chassis of a car, apartition plate 102 is disposed between an ignition source 101 such asan engine, fuel tank, electric system and so forth and the car airconditioner 100. Furthermore, there is also provided a guide member (notshown) for guiding a refrigerant that leaks from the car air conditioner100 to the outside.

[0067] Even if the slightly combustible refrigerant leaks from the carair conditioner 100, the leaked refrigerant is hardly ignited since thepartition plate 102 is disposed between the car air conditioner 100 andthe ignition source 101. Furthermore, even if the slightly combustiblerefrigerant leaks from the car air conditioner 100, this leakedrefrigerant is guided to the outside by the guide member. Therefore, theleaked refrigerant has a lower concentration and is not ignited. Thus,this car is safe.

[0068]FIG. 10 shows a car of another embodiment. In this car, when aslightly combustible refrigerant leaks from the car air conditioner 100,the leakage of the slightly combustible refrigerant is detected by asensor, and fans 105, 105 are driven to forcibly discharge air from theinside of the car. Thus, safety is ensured.

[0069] The driving motor of the car may be any of an electric motor,gasoline-powered engine or hybrid-type engine. Since the car airconditioners of the above embodiments have a high COP, a travel distanceper charge can be extended, and their effect is extremely highparticularly in the case of the electric motor or hybrid-type engine.

[0070] In the above embodiments, the car air conditioner includes afour-way changeover valve 3 and is used for both cooling and heating,but may be used exclusively for cooling without including a four-waychangeover valve. Furthermore, a capillary may be used instead of amotor-driven expansion valve.

[0071] As evident from the above, since the single refrigerant R32 isfilled in the refrigerant circuit in the car air conditioner of thefirst aspect of the invention, its COP is high in comparison with aconventional car air conditioner using the refrigerant R134 a.Therefore, the volume of the cylinder of the compressor can be reduced,the car can be lightened, and thus improvement of fuel consumption canbe achieved. Furthermore, this car air conditioner can contribute toprevention of global warming since the single refrigerant R32 has a lowGWP.

[0072] Furthermore, according to the car air conditioner of the presentinvention, since the single refrigerant R32 is slightly combustible,there are few car fire hazards.

[0073] Furthermore, according to the car air conditioner of the presentinvention, since the single refrigerant R32 is used, recycling of therefrigerant after collection is easy in comparison with a mixedrefrigerant.

[0074] Furthermore, according to the car air conditioner of the presentinvention, since the single refrigerant R32 has polarity, contaminantsand sludge are easily produced, but these contaminants, sludge and thelike are not attached to a capillary or a motor-driven expansion valvedue to vibration and impact of the car, and thus high reliability can beobtained.

[0075] In the car air conditioner of the second aspect of the invention,a mixed refrigerant containing R32 at 70 wt % or more is filled in therefrigerant circuit, there is some difficulty in recycling aftercollection in comparison with the single refrigerant R32, but thisdifficulty is within tolerance. Except for this, almost the samefunctions and effects as those of the car air conditioner of the firstaspect can be obtained.

[0076] Since the car air conditioner of an embodiment includes a scrollcompressor or rotary compressor, compatibility with the singlerefrigerant R32 or mixed refrigerant containing R32 at 70 wt % or moreis favorable, and improvement of durability and light weight can beachieved.

[0077] In the car air conditioner of an embodiment, since a swing-typerotary compressor is used wherein a roller revolves in a casing, a bladefixed to the roller separates a suction chamber and a compressionchamber, the blade is not brought into line contact with the roller andis brought into surface contact with swing bushes, durability is high inrelation to the single refrigerant R32 or mixed refrigerant containingR32 at 70 wt % or more, and the car air conditioner can contribute tolightening of a car.

[0078] Since the car air conditioner of an embodiment has a refrigerantcollection port, a refrigerant can be readily collected.

[0079] Since the car air conditioner of an embodiment is equipped withany of a high-pressure dome-type compressor, low-pressure dome-typecompressor, fully closed compressor, semi-closed compressor or opencompressor, the car air conditioner has favorable compatibility with therefrigerant and can sufficiently function.

[0080] Since the car of the third aspect of the invention is equippedwith the above car air conditioner, this car not only has advantages oflight weight and lower fuel consumption, but also can satisfyrequirements of collection and recycling of the refrigerant.

[0081] The car of an embodiment has an advantage of few fire hazardssince the car air conditioner is hardly ignited even when a refrigerantleaks.

[0082] Since the car of an embodiment has a partition plate between acar air conditioner and an ignition source, a leaked refrigerant is notignited. Thus, this car is safe.

[0083] Since the car of an embodiment has a guide member for guiding aleaked refrigerant from the car air conditioner to the outside, theleaked refrigerant has a lower concentration and thereby is not ignited.Thus, this car is safe.

[0084] Since the car of an embodiment is equipped with the car airconditioner and any driving motor of an electric motor, gasoline-poweredengine or hybrid-type engine, the car has advantages of light weight,lower fuel consumption and favorable efficiency resulting in a longtravel distance per charge particularly when a driving motor is composedof an electric motor or a hybrid-type engine.

What is claimed is:
 1. A car air conditioner, wherein a singlerefrigerant R32 is filled in a refrigerant circuit (1).
 2. A car airconditioner, wherein a mixed refrigerant containing R32 at 70 wt % ormore is filled in a refrigerant circuit (1).
 3. The car air conditioneraccording to claim 1 or 2, wherein the refrigerant circuit (1) includesa scroll compressor (2) or rotary compressor (30, 40).
 4. The car airconditioner according to claim 3, wherein the rotary compressor (40) isa swing-type rotary compressor (40) in which a roller (43) revolves in acylinder (42) and a blade (44) which is fixed to the roller (43)separates a suction chamber and a compression chamber.
 5. The car airconditioner according to any one of claims 1 to 4, wherein therefrigerant circuit (1) includes a refrigerant collection port (8). 6.The car air conditioner according to any one of claims 1 to 5, wherein;the refrigerant circuit includes a high-pressure dome-type compressor(30, 50) in which a motor (32, 51) and a compressing part (52) aredisposed in a casing and a high-pressure refrigerant is filled at leastin a space in the casing (31, 53) in which the motor (32, 51) exists. 7.The car air conditioner according to any one of claims 1 to 5, wherein;the refrigerant circuit (1) includes a low-pressure dome-type compressor(2, 60) in which a motor (25, 61) and a compressing part (62) aredisposed in a casing (20, 63) and a low-pressure refrigerant is filledat least in a space in the casing (20, 63) in which the motor (25, 61)exists.
 8. The car air conditioner according to any one of claims 1 to5, wherein the refrigerant circuit includes a fully closed compressor(2, 30, 40, 50, 60).
 9. The car air conditioner according to any one ofclaims 1 to 5, wherein the refrigerant circuit includes a semi-closedcompressor.
 10. The car air conditioner according to any one of claims 1to 5, wherein the refrigerant circuit includes an open compressor.
 11. Acar equipped with the car air conditioner (100) according to any one ofclaims 1 to
 10. 12. The car according to claim 11, wherein the car airconditioner (100) is hardly ignited even if the refrigerant leaks. 13.The car according to claim 12, wherein a partition plate (102) isdisposed between the car air conditioner (100) and an ignition source(101).
 14. The car according to claim 12 or 13, wherein a guide memberfor guiding a refrigerant that leaks from the car air conditioner to theoutside is included.
 15. The car according to any one of claim 11 to 14,wherein any driving motor of an electric motor, gasoline-powered engineor hybrid-type engine is included.